Executive Benefits Agreements and Employees Savings Plans - Executive Benefit Agreements (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Compensation Related Costs [Abstract]
Total undiscounted death benefits	$ 6,417	$ 6,667
Total accrued death benefits	4,121	4,185
Total undiscounted executive benefits	1,904	1,928
Total accrued executive benefits	$ 1,280	$ 1,365